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https://weedmaps.com/app https://www.leafly.com/apps https://play.google.com/store/apps/details?id=com.smokeio&hl=en
I may actually be wrong. Do these provide deals? They may not provide prices or temporary deals. That would be a great app idea on its own but would take a lot of work to get dispensaries involved and updating prices and specials on the app.