The phrase "added on demand" is correct and usable in written English.
It can be used to describe something that is provided or included only when requested or needed.
Example: "The software features are added on demand, allowing users to customize their experience based on their specific needs."
Alternatives: "included as needed" or "supplied upon request".
The FSN, in its turn, comprises dynamical elements that can be arranged in a multilayered network by a learning process, in which new layers and elementary behaviors are added on demand.
A total of up to 33 sealed reagent vials with liquid capacities of up to 3 mL can be stored upside down in the cassettes and added on demand to any of the three reaction vessels via a Cartesian robot located on top of the instrument and equipped with a vial gripper.
New species are being added on demand, and pathways are being created and edited almost daily.
The classifier for each GO term is independent of the rest of the system; more can be added on demand, even for terms with very few gene products.
Comcast, for instance, has not added live streaming to its iPad app yet; instead, it has focused on adding on-demand programming.
And now, they bought soon-to-be-defunct competing service Rdio for $75 million in order to add on-demand functionality and compete head-on with Spotify (and others).
For a few dollars per month, you can add on-demand music to your Echo speaker, including the Amazon Echo, Echo Dot or Amazon Tap.
So starting today, Google Apps users will be able to add on-demand CRM app Zoho CRM and project management software Zoho Projects into Google Apps.
For Shohoz, that'll initially include food delivery, but there are also plans to add on-demand services — Go-Jek, for example, offers services like groceries, hairdressers or massages on demand.
Following the acquisition of parental photo-sharing app Lifecake in 2015, the company is on a shopping spree again, this time acquiring Kite, a print tech startup that lets developers add on-demand printing features to their apps.
The new product, dubbed WhistleGPS, uses both GPS and sub-GHz cellular technology to add on-demand location monitoring to Whistle's flagship activity tracking gadget that syncs with iOS or Android devices.
