Is there any tools or apps that could help us to manage and change passwords of various accounts that we have?
For someone who have short time memory like me, it's quite pain in the ass every time I try to login to a platform and I have to ask the email for passwords recovery because I keep forgetting the password.
You certainly missed the point that after registering an account, you need to carefully store your data so that there are no incidents, like the one that happened recently, when a person simply forgot their password.
Likewise, do not save your passwords in the browser, since all your cookies can be decrypted, and others can get the password for the forum.
The common advice for account security is using a strong password which is misunderstood by many people. Being unique is the first important specification of a strong password. Because if you use one password on many platforms for multiple accounts, no matter how strong that password is in length and character combination, it breaks basic rule for password setup.
If one platform is compromised, you will have risk of losing all of your accounts that have only one password.
[GUIDE] How to Create a Strong/Secure PasswordUse
Password managers.
And to save passwords, use password managers with an open source code (for example, KeePass, Bitwarden). Or just save them in a blanket encrypted document.
Links to some password manager softwares are above.