folk has a daily message allowance. Character.AI and Janitor AI are free to use with a paid upgrade for more. Kindroid is free to download, and both Kindroid and Nomi list their plans on their own sites.

Where the free versions run out
Memory is the usual limit. On Janitor AI the free tier holds about 9,000 tokens of the conversation, and the paid plan raises that five times. On folk the limit is how many messages you can send in a day, and the count resets at your local midnight.
Free and still useful
Pi is the easy pick if you only want to talk something through. folk is the pick if you want a free friend that also sets reminders, tracks a price or drafts a refund email. You do not need a card for either one.
What free gets you on each one
| App | Free | Paid |
|---|---|---|
| folk | Yes, with a daily message allowance | No paid plan needed |
| Pi | Yes | See its site |
| Character.AI | Yes | c.ai+ at about $10 a month |
| Janitor AI | Yes, on its own model with about 9,000 tokens of memory | janitor+ at $12.99 a month for five times the memory |
| Kindroid | Free to download | See its site |
| Nomi | See its site | See its site |
Which one should you pick?
If free is the only requirement, start with Pi for talking and folk for talking plus chores. Try the paid tiers on the others only once you know memory is what you are missing.