On the other hand, do you know any kind of similar software that is safe to use?
There are open source version of such software, but i wouldn't recommend it unless you bother audit/test it properly. Besides there's saying "Prevention is better than cure". If you haven't done any action, you could start from enabling 2FA on your online account and using stronger password.
or encrypt your computer files when you leave for a long period of time.
It's not practical if you also want to secure your cryptocurrency wallet or browser data, where the file could be scattered on different folder. You could use full disk encryption (such as BitLocker for Windows and LUKS for Linux), but usually you need to enter password/PIN every time you turn on your laptop and recovery process is harder (if the disk is corrupted).