Lumo AI by Proton

I wish Lumo were a more viable AI option, as obviously there’s tremendous upside to having a private LLM that won’t suck up and use your personal data, but Lumo just isn’t ready for wide adoption. To test Lumo, just try asking it about current features on Proton products. I recently spent a half an hour just trying to understand the current state of Proton Pass with respect to certain feature functionality. Lumo very confidently stated that functionality existed that I knew probably did not. I researched the feature in both the documentation and the product and pressed Lumo further to validate its statements. Eventually, Lumo conceded that it was wrong and that its training cutoff dates back to early 2024. It apologized for not being more knowledgeable on Proton product offerings. I personally find this entirely unacceptable. If you can’t trust Lumo to represent Proton accurately, what else is it screwing up? Avoid Lumo for at least another year or two to let the product mature.

I encountered a bug where promotional pop-ups (invite-a-friend ads) would appear repeatedly and erratically every time I opened the side menu. However, I found a solution: clicking the "Invite a Friend" button at the bottom of the menu once seems to fix the UI and stops the glitch. The app is working perfectly now. I wanted to share this fix to help the developers and other users. Great app!

The AI often gave defensive, biased answers, and I often had to fact check and correct it. It’s like arguing with a redditor, denying true objective facts and reframing reality in an effort to not be offensive. I told it not to sugar coat, and it gave me diabetes. The training data is from 2024. Very decent for non-political conversations. I think it gives you bad answers on purpose to make you respond more so that you reach your weekly limit faster pushing you to pay. Proton is great with everything else but this product is skippable. I appreciate the focus on privacy, but the free version needs to be more robust before I would spend money on it.

Upon first opening, on iPhones with Display Zoom enabled there are layout issues… please test with Display Zoom. Also, text size for the response area does not work with iOS’s Text Size control (like for people with vision needs), so the text is really really small. Please make it either respect iOS Text Size changes, or give an option in the app to change text size. Please (and this goes for all your apps)… use a little imagination with your icons. So many developers using white backgrounds… it’s lame and looks unfinished. I do love the cat though! It gives a lot more personality than other chat bots and I enjoy his animation. It makes this app a lot more fun. Thank you for listening to my feedback.

I enjoy using something I know they’re working extra hard to keep my information protected and Lumo AI chats I think are better than other chats because Lumo covers all the bases I think better than chat AI apps - not sure how that’s possible, but seems to be the case!

I love Lumo+. The responses are much better than Claude, ChatGPT and Grok, and all encrypted. PLEASE BRING LARGER FONT TO THE APP (not everyone can see small fonts). And, please stop calling the latest iPhone update iOS 17. It’s iOS 26. Launched at WWDC in June 2025. 😉

I am a paying Lumo+ subscriber, and I am experiencing critical issues that make the app unusable. Data Loss: My chat history is not syncing across devices. Chats appear on my iPhone but are missing from the website and iPad. When I try to copy and paste them into a new thread, they disappear immediately. Performance: The app is severely overheating my phone and consuming excessive CPU, likely because it is running as a web wrapper rather than a native app. Billing Confusion: Despite paying for the 'Unlimited' Lumo+ plan, I am receiving notifications about 'weekly caps' and being treated like a free user. Support has acknowledged the issue is known but has not provided a timeline for a fix, only offering a credit instead of a solution. As a user who relies on this service for safety and continuity, I need a functional app, not just promises. Please fix the sync engine and address the performance issues. We deserve a working product

Installed the new update, I’ll type a question and as soon as I hit send, the app quits. Every time. Reinstalled twice, rebooted iphone, same thing. No error messages. Just quits (crashes) as soon as I hit send.

Once you learn how to use it in the most appropriate way and the corresponding commands, Lumo+ is one of the best!

The new composer was much needed and beyond the look, the app loads way faster and feels snappier!