Few articles
I'm sorry, but I am not sure you have a question or you want us to visit websites.
Is it possible to recover a lost BTC ?
It hugely depends on what means "lost" for each user.
* If the coins were transferred to somebody else's own wallet, bad luck, since confirmed transactions cannot be reversed. The only exception is if the thief makes mistakes and gives up his KYC, but that's also difficult.
* If the user has misplaced his wallet or even removed it, certain tools may help
* if the user has lost access to a centralized service account, he may be able to recover that.
It really depends from case to case. Holding bitcoins is not an easy task, it's a responsibility too many take too easy.
Also, as @Charles-Tim correctly pointed out, many services claiming to recover lost coins are fake / scam.
• Does password crackers app really worked as claimed.
It depends on the password and it depends what you want to crack. Also keep in mind that most of "password protected bitcoin wallets" people sell on the internet are fake.
And cracking bitcoin addresses is not possible.
One has a huge chance that instead of getting/stealing some coins with those crackers, installing malware on his computer and actually lose passwords, accounts, money.