iPeriod 
If you want to create scheduled and repeating invoices you can use the application iPeriod.

Adaptive Invoice
Adaptive Invoice lets you export many invoices from Billogram to PDF at the same time.

Woobill
Woobill is a plugin to WooCommerce web shop and lets you send invoices from your WooCommerce web shop using Billogram.

Jobbile
Complete work orders in Jobbile can be sent for invoicing through Billogram.

Yoddla 
Yoddla is a business system where you can send invoices and repeating invoices directly through Billogram.

Coredination 
Work orders and time reporting in Coredination are compiled into invoicing data and sent using Billogram.

Proposales 
Proposales is a tool where you can create quotes, and then change them to Billogram invoices.

Paloma Event 
Paloma Event tool lets you send invoices directly through Billogram.

Sirvoy 
Sirvoy booking system for hotels can be used to send invoices directly through Billogram.