That will depend on the business model, target market and expected cash flows. Also if the deliverable will be a one time purchase or a recurrent purchase.

If you are targeting mass scale clients, I recommend to go for SaaS . That will help increase your sales very fast, where people can try , pay a monthly fee or per license fee..etc.

If your market is small and you are delivering a high end expensive project, very specialised, I then recommend to go for app .

and you may not even go for a store app. You may then be delivering an on platform app , with even a hardware token or something for licensing , either per user , or a corporate license.

If you want a detailed study I can help you , based on your business plan ( I can help you prepare one ) and assess then and help make models for which one can be better.

Good Luck !