Gemini’s Gems shut-down notice has landed in a lot of inboxes this month. Anyone who spent an afternoon crafting a resume coach, a code reviewer, or a bilingual tutor is now looking for somewhere to move the prompt library before the deadline. The good news is the “system prompt plus memory plus quick launcher” pattern is not unique to Gems, and the best apps for custom AI persona builders now cover free tiers, on-device models, and community-shared personas.
We rebuilt the same four personas we had running in Gems, ported them across eight Android apps, and kept the ones that survive real daily use. The picks below cover every angle: sync-first cloud services, open-source local runners for phones with enough RAM, and community hubs where somebody else has usually solved the persona you were about to write.
What to look for in a custom AI persona app
- A dedicated system prompt field, not just a “start with this text” hint that vanishes after one message.
- Multi-persona switching without losing conversation history for each one.
- Export or JSON copy so the persona survives if the app pivots away from custom bots.
- A reasonable free tier for the most-used persona; paid should only kick in for heavy contexts.
- Voice input if you build personas around walking, driving, or reading with your hands full.
- A model choice, or at least clarity on which model runs the persona.
Quick comparison
| App | Best for | Free plan | Paid starts | Sync |
|---|---|---|---|---|
| Google Gemini | Direct Gems replacement | Yes, with limits | Google AI Pro around $20/mo | Google account |
| ChatGPT | Custom GPTs with tool use | Yes | Plus around $20/mo | OpenAI account |
| Poe | Trying many models per persona | Yes | Poe subscription around $20/mo | Poe account |
| Character.AI | Roleplay and community personas | Yes | c.ai+ around $10/mo | Yes |
| Claude | Long context personas via Projects | Yes | Pro around $20/mo | Anthropic account |
| Ollama | On-device personas with no cloud | Yes, fully | None | Local files |
| ChatterUI | Front end for local and cloud APIs | Yes, open source | None | Local files |
| Perplexity | Research personas with cited answers | Yes | Pro around $20/mo | Yes |
The apps
1. Google Gemini, best for a direct Gems replacement
Google Gemini on Android lets you build custom Gems directly from the app once the migration prompt clears. The saved system prompt, file attachments, and voice input carry across sessions, and the new “Gem shortcut” widget puts your top three personas one tap away from the home screen. The biggest reason to stay in-house is Workspace integration: a Gem that reads your Drive folder still works after the transition, whereas most competitors would need re-permissioning.
Where it falls short: the free tier caps the daily message count on the most capable model, and file uploads still degrade quickly on old phones.
Pricing: free tier available. Google AI Pro runs around $20 per month and unlocks the flagship model with a larger daily quota.
Platforms: Android 10 and up, plus web and iOS.
Download: Aptoide · Google Play
Bottom line: the default choice if all your personas already lived in Google’s ecosystem.
2. ChatGPT, best for personas that need tool calls
ChatGPT’s Custom GPTs system is closer to Gems in spirit than most people realise: a system prompt, uploaded reference files, and optional actions that hit external APIs. The Android app runs your saved GPTs from the top-left switcher without pushing you back to the browser, and voice mode works with any of them. If your Gem was really a “read this doc, then answer in this format” persona, GPT-4o-class models handle that with fewer stumbles than the free tiers of most rivals.
Where it falls short: the GPT store is noisy, and there is no clean export from a Gem definition into a GPT definition, so you rewrite the prompt by hand.
Pricing: free tier for GPT-5 mini and limited GPT-5. Plus at around $20 per month lifts the caps and unlocks Custom GPT authoring.
Platforms: Android, iOS, web.
Download: Aptoide · Google Play
Bottom line: strongest fit for personas that need to call tools, browse, or run code.
3. Poe, best for A/B testing personas across models
Poe by Quora is the app to install if you never quite decided which model your persona should run on. Every custom bot has a system prompt field, a base-model dropdown that spans Claude, Gemini, GPT, Llama, and dozens more, and a knowledge-file section that behaves like Gems’ attached files. Persona chats sync across mobile and web instantly, and you can share a bot with a link without letting the recipient see your prompt.
Where it falls short: the message quota is a shared pool across models, so a chatty persona on a big model burns credit faster than expected.
Pricing: free tier with a small daily quota. Subscriptions start around $20 per month.
Platforms: Android, iOS, web, macOS, Windows.
Download: Aptoide · Google Play
Bottom line: pick this if you want to run the same persona against three different models and keep the best one.
4. Character.AI, best for roleplay and community personas
Character.AI takes the “custom persona” idea in the direction Gems never did: characters with backstories, voices, and community-shared prompts. The Android app opens on a feed of the most-used characters plus your own; making a new one is a form with name, greeting, definition (the system prompt), and optional voice. Long-term memory landed for paid tiers this year, which lets a persona remember the user’s project or preferences across sessions.
Where it falls short: safety filters and refusals lean stricter than most rivals, which frustrates researchers and creative writers alike.
Pricing: free with ads and quotas. c.ai+ starts around $10 per month.
Platforms: Android, iOS, web.
Download: Aptoide · Google Play
Bottom line: the app to pick if community personas save you an hour of prompt-writing.
5. Claude, best for long-document personas via Projects
Claude’s Projects behave almost exactly like Gems for people whose personas revolve around a body of reference material: a system prompt, a set of files, and a chat that stays scoped to them. The Android app now supports Projects switching from the top bar, and Claude Sonnet 4.5 handles the kind of 200-page contract review that used to send a Gem into hallucination territory.
Where it falls short: no tool use on mobile yet, and the free tier’s context window shortens quickly when you attach a big PDF.
Pricing: free tier. Pro at around $20 per month unlocks Projects with the larger context and higher daily quota.
Platforms: Android, iOS, web.
Download: Aptoide · Google Play
Bottom line: best home for a research persona that lives inside a document set.
6. Ollama, best for keeping the persona entirely on device
Ollama on Android runs quantised local models on any phone with 8 GB of RAM or more. Personas are Modelfile snippets: a base model, a system prompt, and optional templates. Because everything runs offline, the same persona survives a plane trip or a country with API restrictions, and no vendor can sunset your saved characters. Recent builds hand off to a phone’s NPU when available, which cuts response latency noticeably on newer Snapdragon and Tensor chips.
Where it falls short: quality still trails the frontier cloud models on general knowledge and long context. Set expectations for a 7B or 14B model, not a 400B one.
Pricing: fully free, open source under an MIT-style licence.
Platforms: Android via community wrappers, Linux, macOS, Windows.
Bottom line: the escape hatch if you never want to migrate personas again.
7. ChatterUI, best open-source front end for mixed local and cloud APIs
ChatterUI is a community-built Android front end that speaks Ollama, OpenAI, Claude, OpenRouter, and koboldcpp servers from the same UI. Personas are called “Character Cards” and can be imported straight from Character.AI or Poe exports, which makes it the fastest way to consolidate a scattered persona library on one device. The prompt editor exposes stop tokens, temperature, and repetition penalty per persona, which nothing on this list except Ollama does.
Where it falls short: the setup ceremony is not trivial. Expect to paste API keys or a local server URL before anything speaks.
Pricing: free, open source. No sign-up.
Platforms: Android.
Download: Aptoide · GitHub releases
Bottom line: the most flexible option for anyone who is happy to trade polish for control.
8. Perplexity, best for research personas with citations
Perplexity treats every “Space” like a research persona: a system prompt, a set of source domains it will and will not search, and an option to attach reference PDFs. The Android app now lets you pin a Space to voice mode, so a driving-friendly market-watch persona reads back cited numbers instead of guessing. When your Gem was really “search the web the way I would”, this is the cleanest port.
Where it falls short: no offline mode and answers can sound assembled when the sources are thin. Manual source curation is a must for niche topics.
Pricing: free tier. Pro at around $20 per month unlocks Spaces with the full model choice.
Platforms: Android, iOS, web.
Download: Aptoide · Google Play
Bottom line: pick this if half your Gems were really “search the web with these constraints”.
How to pick the right one
- If most of your Gems already read your Drive: Google Gemini, no migration.
- If your best Gem calls external tools: ChatGPT Custom GPTs.
- If you want to test the same persona against many models: Poe.
- If your persona is a character with a voice and a backstory: Character.AI.
- If it reads long PDFs and cites them back: Claude Projects.
- If you want no vendor ever to sunset a persona again: Ollama on device.
- If you already run OpenRouter or a local server: ChatterUI.
- If your Gem is a research desk: Perplexity Spaces.
FAQ
Can I export Gemini Gems into another app? There is no one-click export today. Copy the system prompt and any attached file names out of each Gem manually. Save them in a plain-text note so they can be pasted into whichever app you pick.
What is the best free custom AI persona app? For general use it is Google Gemini or ChatGPT, both of which include custom-persona features on their free tiers. If you need zero cloud calls, Ollama is fully free but needs a modern phone.
Are custom AI personas private? Cloud personas are subject to each provider’s data policy. Enterprise tiers usually opt out of training. Only Ollama and ChatterUI with a local server keep persona conversations entirely on device.
Do these apps sync personas between Android and iOS? Gemini, ChatGPT, Poe, Character.AI, Claude, and Perplexity all sync via their account. Ollama and ChatterUI are device-local.
Can I share a custom persona without sharing my prompt? Poe and Character.AI allow this out of the box, sharing only the persona identifier. GPT and Claude expose the prompt to anyone with edit rights, so keep proprietary logic in reference files instead.
