The grades of three Software stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

Vringo Inc. (AMEX:VRNG) is making headway this week, with the company’s rating improving to an A (“strong buy”) from a B (“buy”) last week. Vringo provides products for mobile video entertainment and personalization. For more information, get Portfolio Grader’s complete analysis of VRNG stock.

RealPage Inc. (NASDAQ:RP) is bettering its rating of C (“hold”) from last week to a B (“buy”) this week. Real Page provides a platform of on demand software solutions that integrate and streamline rental property management business functions. Shares of RP have increased 14.3% over the past month, better than the 4.1% increase the Nasdaq has seen over the same period of time.

For more information, get Portfolio Grader’s complete analysis of RP stock.

KongZhong (NASDAQ:KONG) earns an A this week, jumping up from last week’s grade of B. KongZhong delivers wireless value-added services to consumers in China through multiple technology platforms. For more information, get Portfolio Grader’s complete analysis of KONG stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.