I'm a happy user of Zoho Invoice but I need more in terms of project management. I have looked at Zoho CRM but I am not sure it meets my needs.

I am a freelance translator. I have a pool of clients, who send me project offers frequently.

- if I accept an offer, client sends me a purchase order with project specs: name, number, word count, rate, deadline, and instructions if any. 

- I need a program where I can enter this info and shows a clear list of all my ongoing projects, with deadlines.

- When project is completed, I want to change the project status from 'in progress' to completed/uninvoiced. 

- At the end of the month I want to take the list of all uninvoiced projects and move on to invoicing.

Zoho CRM seems to have a ton of features that I won't use (leads, potentials, follow up, etc..) and is missing what I need (workflow from purchase order to invoice and invoice payment). 

I also looked at Zoho Books: it is great because it adds the accounting part of the flow, but it lacks customization of the project feature (it only offers billable hours or flat fee; no deadline, etc..).

I'm wondering whether Zoho Creator would let me create an app that does what I need AND that integrates Z-Invoice or Z-Books. Any ideas? Thank you for your help!