I don't know how incubator/accelerators look at this, but I know that generally speaking investors think of this as a very bad thing. It is not a matter of diversifying risk allowing one product to fail while another product succeeds. It's a matter of amplifying risk.
Starting a single product is very hard. It takes a whole lot of effort, time, energy, and finance to get a product off the ground and viable. By adding a second unrelated product into the mix you are multiplying those tasks. Let's imagine the scenario where the financial services app is doing well in the app store and the social networking website is struggling. The logically thing would be to cut the social network loose and focus on the financial services app. Unfortunately, a co-founder generally won't do that. They will pull the profits from the financial services app and use that to try to save the social networking website. This removes resources from the successful application and pushes them towards the unsuccessful. This probably won't solve the social networks problems, and it will probably cause problems for the financial services app. In the end, both will fail.
Some would say you can build a successful business with related product offerings that are different but complementary. This can be true. It would be like a car company that also owns a finance arm, an insurance arm, and a maintenance arm. All are different but complementary. However, again there is a substantial amount of risk in this and you would have to be well established for an investor the believe you have what it takes to make a business ecosystem like this succeed.
At any rate, I would suggest picking a product and sticking to it. If it fails, then try the other.