Maintaining your vendor contact lists (your "system" support)

[Kevin Phillips]

I use TurboTenant to manage my tenant engagement (leases, payments, maintenance, etc).

I use Stessa to manage my overall Investment Assets.

I have vendor/contractor contacts all stuck in my iPhone and interspersed with my personal contacts.  I want to change this.

My initial search was how to separate contacts in your phone.  This isn't easily done or managed on the iPhone and doesn't really accommodate keeping your personal and business contacts separate.  

Like TurboTenant and Stessa, is anyone using an online platform that allows you to easily manage your contacts and even possibly your interactions with them?  In the larger business space the ERP system would use a finance module to maintain vender relationships and all interactions and transactions with them.  So it may be that this is where I need to consider a more robust system for my accounting work.

Thanks in advance for your feedback/experiences.