Get your child involved, and revise expectations. Your house isn't going to be spotless, and there is always going to be something that needs doing. That's the life of a mom with young kids, and it's okay. No, really, it is.
I am not a fan of using TV as a baby-sitter any longer than you already do, sorry. When it comes to making a toddler more independent, I think screen-time, especially ipads and such, have the OPPOSITE effect. If it was up to me, I wouldn't let your son use the ipad and the phone too often, because kids learn instant-gratification that way and don't know how to entertain themselves. Believe me, I went through this with my oldest, before I knew better, and it's easier to just restrict the screen-time now so that your son can learn sooner rather than later how to keep himself occupied without constant stimulation. I would start regulating that time to no more than 30 minutes a day, too. My kids are allowed 30 (my son is often allowed 60) minutes of educational TV a day (PBS Kids is wonderful: Super Why taught my son to read, and Daniel TIger's Neighborhood actually convinced my daughter to try her vegetables! Not kidding!), and I think letting them learn to play by themselves has been an invaluable lesson. (Having said that, every once and a while, when you're overwhelmed, you can give yourself a break on the screen-time. Just make sure you don't do it every day).
Now, for some tips for the housework, I have a four year old and a two-and-a-half year old, so I've been through this age recently. The best thing I've found is engaging the children in whatever I'm doing. So, your son can "help" in the kitchen, for example. When you need to cook, set him up by the sink with some bubbles and a scrub brush, and you're set! Give him a drawer in the kitchen full of fun (safe) kitchen stuff he can bang around. Turn on the music while you're sweeping/vacuuming/dusting and dance with him. Set up crafts (something as basic as coloring with washable crayons) in the same room with you as you fold laundry. Make really simple meals, like spaghetti with veggies and fruit - you don't have to be a world-class chef!
Your son is old enough to be content in the same room with you without you interacting with him, so get him used to that (believe me, that will come up with another baby). Putting him in the high-chair so you can get something done is FINE.
It will be harder, at first, with two, but eventually, they'll be able to play together while you work. You'll get there. Best of luck.