I have tried it before. Android app is paid. It just gives trail previews with a watermark. Even that didn't work for me properly.
casting to chromecast is free.
Bubbleupnp is the best for it. Using if for more than 3 years for movies with subtitles with no problem.I want to view movies in mobile ( with subs ) on TV, using Chromecast 2. What should I do ?
Casting to plex when the plex server is on local network is free. Casting to the android app is paid (unless you have the plex pass)
Pretty sure even for remote its free, you need to open up the ports, remember!
keep all my movies/series with subs in a pendrive and then just access the pendrive with TV remote.
there's an option of connecting a display using Wi-Fi which will mirror your phone screen
In android phones there's an option of connecting a display using Wi-Fi which will mirror your phone screen on your TV. You can then play your movie on your phone.
Alternately, I've found it way more convenient to keep all my movies/series with subs in a pendrive and then just access the pendrive with TV remote.