Plimm is a journal for iPhone and Android whose AI runs on the phone itself. Write or talk, and it reflects back, asks questions and finds patterns in your mood over the weeks. No account and no Plimm server: after a one-time 437 MB download, everything works in airplane mode. Built on llama.cpp (Qwen2.5-0.5B) and whisper.cpp. Free: unlimited writing, one AI conversation a day, 30-second voice notes. Pro: $4.99/month or $39.99/year.