Jim Cramer, TheStreet's portfolio manager for Action Alerts PLUS and host of CNBC's "Mad Money," said Fitbit's (FIT) - Get Report earnings report was the best beat of 2015. He's a believer in the company, he said.

But Fitbit has filed an offering to sell shares, so Cramer sees it heading lower. When it does, that's the opportunity to buy, according to Cramer.

The comments were made as Cramer answered viewers' questions from social media on the floor of the New York Stock Exchange Tuesday.

One viewer asked whether to buy FireEye (FEYE) - Get Report ahead of its earnings report. Cramer noted FireEye's stock advanced on Monday, so investors should be careful because he believes the entire sector is trending lower.

Another viewer asked if LinkedIn (LNKD) can get back up to $300 after reporting an excellent quarter. Cramer compared the company to Facebook (FB) - Get Report and Google (GOOGL) - Get Report , and applauded its subscription growth. He added that he wouldn't be shocked if the stock continues to work its way higher.

Cramer was asked whether Blackberry (BBRY) stock can climb and whether CEO John Chen's turnaround strategy is working. Cramer gave an uncharacteristically terse answer: "No."

Another viewer asked whether VeriFone (PAY) is still a good long-term play. Cramer said the stock has been a huge disappointment, like NXP Semiconductors (NXPI) - Get Report . But he said the future is brighter for that stock, because companies need their equipment.

Cramer was asked about Mondelez (MDLZ) - Get Report , which he said does have a lot of growth ahead of it, as well as opportunity to cut costs. He noted two big investors -- Bill Ackman and Nelson Peltz -- both own the stock.

Cramer was asked about Icahn Enterprises (IEP) - Get Report . He wouldn't comment on that stock specifically, but suggested that investors buy AIG (AIG) - Get Report , a company that Carl Icahn is trying to shake up.

Finally, Cramer was asked about SandRidge Energy (SD) - Get Report . He responded that SandRidge, Magnum Hunter (MHR) and Energy XXI (EXXI) are all companies that will find it very hard to stay in their current equity form, given the decline in oil prices.

Cramer answers viewers' social media questions during a daily segment with TheStreet TV. Find him on Facebook (FB) - Get Report and on Twitter (TWTR) - Get Report . Send him questions on Twitter @JimCramer, using #CramerQ.