'promising application' is a correct and usable phrase in written English.
For example, you could use it in a sentence such as, "This new technology has a promising application in the medical field."
The most promising application of nanomaterials is the promise of targeted, site-specific drug delivery.
Another promising application is in touring entertainment.
Another promising application is Safe Mobile Care.
THE most promising application so far is retirement savings.
This most promising application of buckyballs involves breaking them apart.
A promising application of high-dimensional OAM states is their use in quantum cryptography schemes.
The most promising application of this emerging technology is in medicine.
The PACT-IAQ has promising application in indoor pollutant control.
Such systems are a promising application of solar energy systems.
These properties suggested their promising application in cancer therapy.
More promising application of the artificial organelle is to use as the phosphate recycling system in cell-free system.
