Background and History
Sweetsop, better known in the West as the sugar-apple is a very unique fruit that is said to be a native of the tropical regions of the Americas, where it has been consumed as a foodstuff by aboriginals since before the Colonization. Despite being said to have originated in the Americas, sweetsop is most commonly enjoyed in several parts of Asia, where it is a well-known and well-loved dessert fruit.
Sweetsop is a medium-sized semi-evergreen shrub or tree that grows up to twenty-six feet tall in most mature species. Now commonly found in waste places or untended lots that have a profusion of moist, loamy soil, its features are relatively indistinct from many other trees and shrubs that thrive in such areas, replete with medium-sized oblong leaves that slightly taper to a point. The most discernable qualities of the sweetsop tree are usually its flowers which are of a jade-like hue coupled with a markedly identifiable purple spots beneath the stems where they grow in clusters. It is the fruit of the sweetsop however which possesses the most distinctive characteristics of the plant. A medium to large-sized fruit of a decidedly greenish hue when unripe, and a purplish to black colouration when mature, it is notable for its pinecone-like appearance and unique, leathery-looking outer covering replete with barely discernable scales and highly discernable lumps. 
The sweetsop fruit houses a juicy, succulent flesh that is intermixed with a number of small, black, shiny seeds. The flesh of the fruit is notable for its decidedly custard-like taste, aroma and mouth-feel, making it something of a novelty for individuals who've yet to try it. Sweetsop fruits are also well-known for their highly discernable aroma which has the tendency to pervade an entire area when ripe and scent the air with the nearly perpetual aroma of custards and cream. Because of its fragrant nature, sweetsop, when cultivated, is typically planted in gardens to lend a very comforting, soothing, and noticeably hunger-inducing aroma. Despite being intensely popular in Asiatic countries, sweetsop enjoys very little popularity in its native soil, and because of this, most Asiatic countries such as the Philippines consider sweetsop to be more of a 'local' oddity than an introduced species.
Common / Popular Users
The most common use of sweetsop has been and continues to be as a foodstuff. Typically consumed in its raw, ripe form, sweetsop is enjoyed chiefly by children and the elderly for its mellow sweetness. Because of its slightly creamy texture, sweetsop may also feature as a base or an additive to desserts such as slushes and slurries. It may even sometimes be prepared into jams, jellies, or preserves, but this is rarely done, as heating sweetsop drastically changes its flavor profile and destroys most of its vitamin content. Sweetsop is an excellent source of easily absorbable iron and Vitamin C, making it an excellent fruit to consume on a regular basis. Sweetsop also contains significant amounts of fibre, and regulated consumption of the fruit for therapeutic purposes such as for treating obesity, diabetes, or for detoxification is quite commonplace in Asian settings. When unripe, the fleshy part of the fruit may be crushed and made into a poultice to help soothe burns and wounds and to alleviate the discomforts brought about by bites from most poisonous insects. When ripe, it may be pureed and employed as a hair and facial mask due to its moisturizing and antibacterial properties. 
Aside from its edible fruit, the sweetsop tree is also a pharmacopoeia unto itself. Its leaves, when employed in its fresh or dry form as a very potent decoction can be used as a warming bath to help relieve discomforts brought about by chills or arthritis. Milder decoctions of the leaf may be drunk as a tisane to help soothe bowel discomfitures and treat a wide array of digestive problems. Left to macerate in coconut oil (or any other type of base-oil), it can be used as a liniment for rheumatism, gout, and general aches and pains. 
A decoction of a combination of its roots and bark has been employed by Filipino shamans as general invigorating tonic, and as a remedy for diarrhea, indigestion, and colic. More potent brews typically yield powerful purgatives that are employed to rid the body of intestinal parasites. 
The seeds that are found in profuse numbers within the body of the fleshy pulp itself have been employed since ancient times as a type of natural insecticide. In traditional Filipino folkloric medicine, the seeds of the sweetsop are typically ground or pounded into a semi-fine to fine paste and then left to infuse in coconut oil. This is then applied liberally all throughout the head and allowed to remain overnight, to be washed off the next day. This effectively gets rid of head lice in all stages of evolution. The seeds may also be decocted, and the resulting liquor employed as a hair rinse, or otherwise used to water plants that are prone to insect attacks, as the seeds contain powerful insecticidal properties. 
While tisanes of sweetsop leaves must be avoided by pregnant and lactating women, the consumption of the fruit is strongly encouraged due to its significant bioavailable folate and copper content. Moderate doses should be observed however, as it may cause abortifacient side-effects if consumed in very high dosages.
Despite sweetsop's vast range of medicinal applications, there is very little magickal use for the fruit within the Western esoteric traditions. In Filipino shamanic culture however, sweetsop trees are believed to be choice 'homes' for fair-folk or elementals, while its fruits make for excellent offerings to anitos or forest spirits. The dried leaves of the sweetsop plant is usually made into a medicated liniment employed by shamans in undoing hexes and enchantments.
Names of Sweetsop, past and present
Chinese: fan li zhi / shijia
Indian / Sanskrit: ata / shareefa / seethaphal / aathachakka
Indonesian: srikaya / srimatikiya
Filipino: atis / yates / ates
Arabian: qishta / ashta
Spanish: anon de azucar / anona blanca / granadilla
English: sugar-apple / sweetsop / custard apple
Latin (scientific nomenclature): Anona squamosa / Anona asiatica