1. Some Weather Applications.
Certain weather apps are not good for your phone. This is due to the fact that many of them have been found to actually have viruses and sometimes they collect your data from your phone and send it to the people who own the application without your knowledge.
2. Optimising Applications.
Optimising applications are sometimes also not good for your mobile phone.
Sometimes they do unnecessary things like clearing your cache. But the truth is that most phones have all of these functions anyway.
New versions of operating systems that have been released have these functions built internally on the device and this makes optimising applications pointless.
All they do is make your battery life a lot shorter since the clearing cache activity will require some power from your battery to do so.
3. Antivirus Applications.
Another thing you have to know is that unknown antivirus applications are also not good.
Sometimes viruses are disguised as antivirus apps. Some antivirus applications run both background and foreground on your smartphone.
This means that more battery power will be dedicated to these functions and you will experience poor battery efficiency. Coupled with this, your device will run slow.
4. RAM Applications.
Apps which save and increase your RAM memory are also scams. In actuality what they can do is to temporarily clean your cache. There is no way to get more RAM on your smartphone because it is fixed unless you buy a totally new phone which possesses a bigger RAM.
Source; opera news