I helped build Rubberstamp (www.rubberstamp.io) which solves this problem. Its a super simple purchase order management system that works on mobile and directl

I helped build Rubberstamp (www.rubberstamp.io) which solves this problem. Its a super simple purchase order management system that works on mobile and directly though emails for approvers. We'll be building support for recurring orders, delivering checking very soon. If you're interested in a trial then just let me know!