Free weight alternative exercises

[outlander]

I found these very interesting. I already do a few of them, but I really wonder if they can replace using free weights?

 

[outlander]

These look good. I tried a bit and got some popping in my lower back (the good kind) and could feel an improvement in flexibility immediately.

 

[Michael Z]

I do those static hold push-ups, but not like they are shown in the top video. Rather, I do mine inclined a little the other way (up) to reduce the load on my shoulders a bit. Form matters a lot!