PS4 Pro on 4.55. Is there any way I can install a free app?

Hi, I am not new to modding but I am new to the PS4.

I have a PS4 Pro on 4.55. There's a free app I would like for it, but I obviously cannot connect my PS4 to PSN to download it. Is there any way to get it on my system?

Also kind of off topic but is there any way to use remote play with a modded PS4? I don't care about playing games online or multiplayer; I just wanted to know if I can utilize remote play (on a Vita or Android) with a modded console.

Thanks in advance!