I use Verizon Messages+. I just downloaded Textra to see what all the fuss is about. I'll have to play around with it a few days and see what I can do.
Messages+ is very customizable, allows you to text from any device using your cell number and you don't have to have Verizon to use it. I use it on my tablet, desktop, laptop, and of course my phone.
It will also text over wifi on any of your devices. So if you have a wifi only tablet it will work just fine on Messages+.
Also allows scheduled text.