Some context: Zhang Heng (Chinese: Zhang Heng ; AD 78-139), formerly romanized as Chang Heng, was a Han Chinese polymath from Nanyang who lived during the Han dynasty. Educated in the capital cities of Luoyang and Chang'an, he achieved success as an astronomer, mathematician, scientist, engineer, inventor, geographer, cartographer, artist, poet, statesman, and literary scholar. Zhang Heng began his career as a minor civil servant in Nanyang. Eventually, he became Chief Astronomer, Prefect of the Majors for Official Carriages, and then Palace Attendant at the imperial court.
Zhang Heng is often credited with inventing the first odometer, an achievement also attributed to Archimedes (c. 287-212 BC) and Heron of Alexandria (fl. AD 10-70). Similar devices were used by the Roman and Han-Chinese empires at about the same period. By the 3rd century, the Chinese had termed the device the ji li gu che, or "li-recording drum carriage" (the modern measurement of li = 500 m/1640 ft).  Ancient Chinese texts describe the mechanical carriage's functions; after one li was traversed, a mechanically driven wooden figure struck a drum, and after ten li had been covered, another wooden figure struck a gong or a bell with its mechanically operated arm. However, there is evidence to suggest that the invention of the odometer was a gradual process in Han Dynasty China that centered on the "huang men"--court people (i.e. eunuchs, palace officials, attendants and familiars, actors, acrobats, etc.) who followed the musical procession of the royal "drum-chariot". There is speculation that at some time during the 1st century BC the beating of drums and gongs was mechanically driven by the rotation of the road wheels. This might have actually been the design of Luoxia Hong (c. 110 BC), yet by at least 125 the mechanical odometer carriage was already known, as it was depicted in a mural of the Xiao Tang Shan Tomb.  The south-pointing chariot was another mechanical device credited to Zhang Heng. It was a non-magnetic compass vehicle in the form of a two-wheeled chariot. Differential gears driven by the chariot's wheels allowed a wooden figurine (in the shape of a Chinese state minister) to constantly point to the south, hence its name. The Song Shu (c. AD 500 ) records that Zhang Heng re-invented it from a model used in the Zhou Dynasty era, but the violent collapse of the Han Dynasty unfortunately did not allow it to be preserved. Whether Zhang Heng invented it or not, Ma Jun (200-265) succeeded in creating the chariot in the following century.
Was there anything else he created?
A: inventing the first odometer,
Some context: Ai Otsuka (Da Zhong  Ai , Otsuka Ai, born September 9, 1982) is a Japanese singer-songwriter from Suminoe-ku, Osaka, Japan. She is a popular artist on the Avex Trax label and is best known for her 2003 hit "Sakuranbo," which stayed in the Top 200 Oricon Weekly Singles Chart for 103 weeks. A piano player since age four, Otsuka composes and co-produces her own songs, as well as writes her own lyrics. Her music ranges from upbeat pop/rock music to ballads.
In April 2006, Otsuka released "Frienger" (a portmanteau of the words Friend and Ranger). The promotional video was shot in Taiwan and was used as the commercial song for the Toshiba W41T 4 GB MP3 mobile phone. Soon after the release of "Frienger," Otsuka reprised her role as an actress for Tokyo Friends: The Movie, which hit theaters in Japan on August 12, 2006. The movie is a direct sequel to the DVD drama released the previous year. Otsuka also sang the opening theme for Tokyo Friends, "Yumekui", which was released as a new single on August 2, 2006. It debuted fifth on the weekly chart, selling 63,428 copies in the first week and a total of 145,281 copies.  Two months after "Yumekui", Otsuka released another single titled "Renai Shashin" on October 25, 2006, which was used as the opening theme song for the movie Tada, Kimi o Aishiteru. The song was based on events from the film and its original novel, also called Renai Shashin. "Renai Shashin" debuted at number 2 and sold 129,855 copies, making it the 75th best-selling single of the year. At the end of 2006, Otsuka had released a total of three singles and charted on Oricon's 2006 yearly chart with "Frienger" at number 60, "Yumekui" at number 66, and "Renai Shashin" at number 75.  Otsuka released her fourteenth single, "Chu-Lip," on February 21, 2007. The single was used as the theme song for the TBS drama Kirakira Kenshui, starring Manami Konishi and Wentz Eiji of WaT and managed to claim the third position on the Oricon charts.
What was the last song she released?
A:
Otsuka released her fourteenth single, "Chu-Lip," on February 21, 2007.