I've used Venmo, PayPal and currently I use Cozy, except for one person who still pays by check. 

I want to use Cozy for my expense manager but do you ahve any other suggestions?

I just started using cozy!

It’s well appointed,  but more cozy than fancy,  leaning towards rustic.  

If they're good tenants, they have a bank account, and would welcome the ease of paying online and automatically via Cozy, it's free.

I've been using Cozy to manage my own property, but I'm wondering if I need to look into some different software as I start managing property for others.   

Cozy is free if you use a bank account, but charge the tenant a 2.75% fee if using a debit or credit card. 

Cozy also has online rent payment and syndicates apartment listings to a few sites (realtor.com, doorsteps.com) as well so it's a good tool for small landlords. 

Cozy offers a faster payment for $3/unit... but not worth it to me.I really like Cozy because it's focused towards landlords and tenants. 

I also ask other questions that cozy & mysmart move do not ask.if you want something that just is a form and gets their permission Wufoo.com is free form creator that will send the form answers to your email.