You can find the ones that sync directly to it on the Samsung Health app (hint: there aren't many). HOWEVER, most scales will have either a plug in to sync into Samsung Health or Google Fit, and you can link those two and 'share' data between them (so, for instance, if you get a scale that only syncs data with Google Fit, you can link your Fit and Health accounts and then Samsung will just copy over whatever is on Fit, and viceversa). For Blood Pressure stuff, however, things get trickier. I'd go either with the brands/models that sync directly to Samsung Health, or with a brand that's confirmed lately to do it (Withings' armbands, for instance, used to sync OK with Google Fit, but now BP specifically is left out in the dust).