I want to control my laptop from my mobile phone?

Which app can I use best?

Teamviewer

You mean as a remote method?

What should be controlled?

take a look: KODI

I want to control my Lenovo with my Android smartphone

Can I then also start and operate programs from my mobile phone?

In my opinion, Anydesk is the best free solution

Yes, it is possible

Anydesk is also very convincing, and steam play is perfect for video transmission (just install the calculator as an external app in steam and then minimize it in the stream in the steam player, zack you are at home with 60fps and 1080 resolution on the desktop, on your mobile phone With sound and min 21fps utube stream from the remote browser.

alternatives are created by google with its online plugin or SSH connections via a network tunnel and an API that sits behind an app such as remote clients that can be bought in the app store on the mobile phone in all mOS

I think so. So it's about lending my Lappi to my grandma and if she gets stuck, she can start movies and the Internet from her cell phone.

Then I recommend the best teamviewer.

The mouse? Keyboard?

I recommend anydesk or steam play. They have fps and are implemented moderately well. Steam also takes mobile gaming to a new level, or offers you a nice controller on your smartphone.

Yes

Install TeamViewer for remote access… Then you can access the computer at any time and control it completely remotely as if you were sitting in front of it yourself… Your grandma only has to switch the lappi on…