We have published the Delivery Order Signed and Tracked application to the entire Odoo Community.

You can download it using the link below.
https://github.com/JayVora-SerpentCS/DOST/tree/12.0

If this is interesting to you and your clients, please have a look and send your feedback.
Whoever wishes to try a mobile app, they can download using the link below.

https://www.dropbox.com/s/zxfviw4i8gtbaud/Dost_app-release.apk?dl=0

This module may be useful as it is OR you can make further customisation as per your / client requirement.

DOST v1 - Delivery Order, Signed and Tracked - in Odoo

Have a look at the video.

DOST v2 - Delivery Order, Signed and Tracked - in Odoo by SerpentCS

Serpent Consulting Services Pvt. Ltd.  Presents a delivery boy-friendly mobile app working with Odoo. The application helps the delivery boy get the order confirmed, signed and tracked and the data is sent to server. The app works both for Android and iOS.

Have a look at the video.

Thanks.